They told him among other things that every bid except his had been in for two weeks, and that they were in the vault under the care of Mr. Pitts, the head draftsman.  They promised to advise him if any new bids came in or if any changes occurred, and, most important of all, they told him that in England all structural steel shapes, instead of being classified as in America, are known as “angles,” and they told him just how and where to find the official reports giving the price of the same for every day in the year.

The word “angles” was the missing key, and those official market reports formed the lock in which to fit it.  Mitchell had taken several mighty strides, and there remained but one more step to take.

When his guests had finally gone home, swearing fealty, and declaring this to be the best dinner they had ever drunk, he hastened back to his room, back to the desert of blueprints and to the interminable columns of figures, and over them he worked like a madman.

He slept two hours before daylight, then he was up and toiling again, for this was his last day.  Using the data he had gathered the night before, he soon had the price of English and Scottish steel at the time the last bids were closed.  Given one thing more—­namely, the cost of fabrication in these foreign shops, and he would have reduced this hazard to a certainty, he would be able to read the prices contained in those sealed bids as plainly as if they lay open before him.  But his time had narrowed now to hours.

He lunched with John Pitts, the head draughtsman, going back to pick up the boomerang he had left the week before.

“Have you gone over my first bid?” he asked, carelessly.

“I have—­lucky for you,” said Pitts.  “You made a mistake.”

“Indeed!  How so?”

“Why, it’s thirty per cent. too low.  It would be a crime to give you the business at those figures.”

“But, you see, I didn’t include the sub-structure.  I didn’t have time to figure that.”  Mitchell prayed that his face might not show his eagerness.  Evidently it did not, for Pitts walked into the trap.

“Even so,” said he; “it’s thirty per cent. out of the way.  I made allowance for that.”

The boomerang had finished its flight!

Once they had separated, Mitchell broke for his hotel like a hunted man.  He had made no mistake in his first figures.  The great Krugersdorpf job was his; but, nevertheless, he wished to make himself absolutely sure and to secure as much profit as possible for Comer & Mathison.  Without a handsome profit this three-million-dollar job might ruin a firm of their standing.